Machine for separating hulled from unhulled grain.



PATENTED MAR. 17, 1908.

A. P. MAODONALD. MACHINE FOR SEPARATING HULLED FROM UNHULLED GRAIN.

APPLICATION FILED APR. 18, 1907.

2 SHEETS-SHEBT 1.

PATENTED MAR. 17, 1908.

' A. P. MAODONALD. MACHINE FOR SEPARATING HULLBD FROM UNHULLBD GRAAPPLICATION FILED APR.18,1907.

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UNITED sTATEs PATENT oEEicE.

ALEXANDER I. MACDONAL D, OF MORRIS, ILLINOIS.

MACHINE FOR SEPARATING HULLED FROM UNHULLED GRAIN.

Application filed April 18, 1907.

Specification of Letters Patent.

Patented March 17, 1908.

Serial No. 368,976.

To all whom it may concern:

Be it known that I, ALEXANDER l?. MAC- DONALD, a citizen of the UnitedStates, residing at Morris, in the county of Grundy and State ofIllinois, have invented certain new and useful Improvements in Machinesfor Separating IIulled from Unhulled Grain, of which the following` is aspecification.

This invention relates to the general art of grain-separating machines,and has reference more particularly to that class of machines which isdesigned and `adapted to take the product of the hulling ordecorticating machine and effect a separation of the hulled grains orkernels from the unhulled.

The type of machine on which my present improvements are based isillustrated by the grain-separating machine shown in United StatesLetters Patent to Friedrich H. Schule, No. 559,815, dated May 12, 1896,and No. 726,996, dated May 5, 1903; the principal features of saidmachine residing in a sloping table having formed across its top aplurality of arallel channels with staggered zigzag wa s and rentrantangles, in combination with means for reciprocating or shaking the tablein a direction transverse to the channels, and means for feeding the material into said channels, whereby the heavier grain particles settle tothe bottom and slide down the channels, discharging at the lower ends ofthe latter, while the lighter particles, consisting of the unhulledgrain, blind grains, seeds, and foreign matter generally, is buffetedback and forth between the oppositely inclined walls of the channels,which thus act as a conveyer to deliver such material off at the upperends of the channels. In the practical operation of these machines ithas been found necessary to pass the grain through a series of suchmachines or through a series of operations in a single machine, in orderto get fairly satisfactory results.

My present invention resides chiefly in an im rovement on this type ofmachine wherebypI am enabled to effect a thoroughly clean separation ofthe hulled grain from the unhulled grain and waste matter at a singleoperation, thus saving the waste of time and expense involved in passingthe material through several machines or operations, as has heretoforebeen necessary.

The machines of the type above referred to operate as describedprincipally by reason of the fact that the kernel or hulled grain itselfis heavier in proportion to its volume than the unhulled, partly hulled,blind grains, and foreign matter, by virtue of which it settles to thebottom where it rests on the floor of the channel, and is thereforesomewhat less subject to the agitating action of the table than thelighter material, which latter, rising to the top and possessing greatersmoothness of surface, is thrown back and forth between the side wallsof the channel and, by virtue of the peculiar form of the latter, isworked out of the channels in a direction opposite to the flow of thehulled grain. IfIeretofore, so far as I am aware, the bottoms of thechannels of these machines have been made with smooth polished metalsurfaces. The result of this has been that both the hulled and theunhulled grain moves from side to side of the channel in a body, andquite a percentage of the hulled g-rain finds lodgment in the rentrantangles of the channels out of the path of the main flow of the hulledgrain and is thrown back and forth between the side walls with theunhulled grain and finds its way out with the latter, thus going towaste unless subjected to a further separating operation.

I have discovered, as a result of numerous experiments and tests, thatif the bottom wall of the channel, instead of being made perfectlysmooth as heretofore, be given a frictional character, such as to retardand check the transverse movement of the hulled grain on the bottomunder the shaking of the table, the hulled grain will remain in thecenter of the channel unaffected by the action of the side walls andreadily 'flow down the channel, while the unhulled grain on top isbuifeted back and forth between the oppositely inclined side walls ofthe channel and is conveyed and discharged in the opposite direction.For the purpose of a frictional surface to the bottom wall or floor ofthe channel, I prefer a covering or carpet of India rubber; but the gistof my invention resides in nn king such bottom wall or floor of thechannel of a roughened or frictional character, irrespective of theparticular material employed, for the purpose of checking the transverse'flow of the hulled grain under a throw of the table su'flicient tobuffet the unhulled grains between the side walls of the channel.

My invention will be readily understood when considered in connectionwith the accompanying drawings, wherein,-

Figure 1 1s a side elevational view of a grain-separating machineequipped with my present improvements. Fig. 2 is a plan view on anenlarged scale of the channeled table, with the feed-trough broken awayat one end; and Fig. 3 is a cross-sectional view on the line 3 3 of Fig.2.

Referring to the drawings, and iirst brieiiy describing the principalmechanical elements of the machine, such as are shown in both of theSchule patents above referred to, to which reference may be had for afuller description, 5 indicates as an entirety the separating table,which is secured to longitudinal beams 6, mounted on sectoral rockers 7,the segmental faces of which latter are provided with gear teeth meshingwith racks 8 on a suitable base-plate or on longitudinal beams of aiioor frame; and to the longitudinal beams 6 aboutmidway of their lengthis connected one end of a connecting rod 9, Whose opposite end receivesan eccentric strap 10 surrounding an eccentric 11 on a driving shaft 12mounted in journal bearings 13 on suitable pedestals 14. Springchusioning devices 15 are applied to the opposite ends of the rockers 7,in order to cushion the shocks of the machine.

Referring now to the structural features of the separating table proper,16 designates the flat top of the table that may be supported on properlongitudinal and transverse frame members 17 and 18, and is given aninclination or slope in the direction of its shortest dimension, asclearly shown in Fig. 3. To the upper surface of the table top isapplied, in the embodiment of the invention erein shown, a frictionsurface in the nature of a carpet or covering of rubber, leather, felt,or other similar friction material indicated at 19; and on said carpetor covering are secured the zigzag walls of the channels. Each wall isconveniently formed, as herein shown, by a series ofalternatelylaterally oilset prism blocks 2O and 21, the alined parallelfaces 0f adjacent blocks being connected by sheet metal or other stripsor plates 22.

y virtue of this construction there are formed between adjacent rows ofprism blocks zigzag channels indicated by 23 eX- tending from onelongitudinal side or edge of the table to the other, into which channelsthe grain to be separated is fed through a superposed feed-box or trough24 provided with adjustable valves 25 (Fig. 3). It will be observed thatthe ends of any inclined wall on one side of a channel lie opposite thecenters of similar walls on the opposite side of a channel, the purposeand result of which is to throw the unhulled grains forming the upperlayer of the material in the channels back and forth across the latterin a zigzag manner of travel toward the upper edge of the table. Thehulled grain, on the contrary, being liner and heavier, and furthermorepossessing a less smooth surface than the unhulled grain, clings to thefrictional surface of the bottom wall of the channel, and by virtue ofthe frictional or adhesive character of the latter, is kept out of thereentrant angles, and under the continuous shaking movement, aided bythe effect ofgravity, slides downwardly of the channels and isdischarged from the lower edge of the separating table into a trough orchannel indicated at 26 (Fig. l) suitably placed to receive it.

I have discovered that by giving to the bottom walls of the channels africtional character in lieu of the smooth polished metal surfaceheretofore used, I effect a perfect and complete separation of thehulled from the unhulled grain by a single passage through the machine.The frictional surface so retards the transverse movement of the hulledgrain at the bottom as to keep it in the center of the channel, thus notonly giving a perfect separation in one operation, but eliminating allwaste caused by the working of the hulled grain upwardly with theunhulled, which occurs to a considerable eX- tent in the machines now inuse. At the same time, this frictional surface has no ef fect upon thetravel of the unhulled grain, inasmuch as its travel is on top of thehulled grain.

Different materials give slightly dierent degrees of efficiency; and themost eficient material I have thus far discovered for the purposedescribed is ordinary vulcanized rubber; but I would have it understoodthat my invention comprehends any material or roughened surfaceswhatever having the character of what I term 'a friction surface ormaterial.

I am aware that the use of a friction surface on an endless carrier in agrain-separating machine is old, in which the friction surface causesthe rougher surfaced particles of the grain to cling thereto and bepositively carried to the end of the carrier and discharged, and I makeno claim to such use of a friction surface in a grain-separatingmachine; but the friction surface on the bottoms of the channels of mypresent invention operates in a different way and upon a different andnovel principle. In the first place, this friction surface is not formedupon an endless belt or carrier, and consequently has no function topositively carry oif a separated part of the grain through a clinging oradhering action but rather it is formed upon a shaking surface that isinclined in the direction of the channels, and its function is to retardthe momentum of the hulled grain on the bottom suliiciently to preventits being thrown against the zigzag side walls, thus permitting thecombined action of gravity and agitation to eect its discharge at thelower end of the channels, while the smoother and somewhat lighterunhulled grain, by virtue both of the fact that it naturally rises to4the top of the mixture under the agitation and of the further fact thatit is of a smoother surface than the hulled grain, is buffeted back andforth between the side walls and thus directed toward the upper ends ofthe channels. In other words7 the machine of my invention prevents thehulled grain on the bottom and the unhulled grain on the top from movingtogether in a body, as they do in machines wherein the bottom of thechannel is of smooth or polished metal.

I claim:

l. In a machine for separating hulled from unhulled grain, atransversely inclined separating table provided on its upper surfacewith a series of transversely extending chan nels formed with zigzagside walls and friction-surfaced bottom walls, in combination with meansfor feeding grain to said channels at points intermediate the ends ofthe latter, and means for imparting a shaking movement to saidseparating table in a direction transverse to said channels whereby theunhulled grain is buffeted back and forth between the side walls anddischarged at the i higher endof said channels while the hulled grain isretarded by said friction-surfaced bottom walls against Contact withsaid side walls and descends under the combined action of gravity andagitation to the lower ends of said channels from which it isdischarged, substantially as described.

2. In a machine for separating hulled from unhulled grain, atransversely inclined separating table provided on its upper surfacewith a series of transversely extending channels formed with staggeredzigzag side walls and rubber-surfaced bottom walls, in combination withmeans for feeding grain to said channels at points intermediate the endsof the latter, and means for imparting a shaking movement to saidseparating table in a direction transverse to said channels whereby theunhulled grain is buffeted back and forth between the side walls anddischarged at the higher end of said channels while the hulled grain isretarded by said rubber-surfaced bottom walls against contact with saidside walls and descends under the combined action of gravity andagitation to the lower ends of said channels from which it isdischarged, substantially as described.

ALEXANDER P. MACDONALD.

